// Written in the D Programming Language
/*
 * Copyright (c) 2008 OpenGLUtils
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'OpenGLUtils' nor the names of its contributors 
 *   may be used to endorse or promote products derived from this software 
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
module openglutils.TextureLoader;

import openglutils.GL;
import openglutils.GLU;
import openglutils.SDL;
import openglutils.GLTexture;

import tango.stdc.stringz;

/**
 * The TextureLoader provides methods for loading OpenGL textures. See the individual functions for help on how they
 * function.
 * 
 * NOTE: This class is not something I like, so it might get changed/deleted without notice.
 */
public class TextureLoader
{
	/**
	 * Loads a single texture using the given image filename.
	 * 
	 * Note: Only BMP images are supported
	 * 
	 * Params:
	 *     fileName = the name of the file from which the texture is loaded
	 *     minFilter = the min filter for the texture, default: GL_LINEAR
	 *     magFilter = the mag filter for the texture, default: GL_LINEAR
	 *     mipMapping = will mipmapped textures be generated, note that the minFilter should be GL_LINEAR_MIPMAP_NEAREST
	 *     	when using this, default: false
	 * Returns: The loaded texture or null if the image loading failed.
	 */
	public static GLTexture2D loadTexture2D(char[] fileName, GLuint minFilter = GL_LINEAR,
		GLuint magFilter = GL_LINEAR, bool mipMapping = false)
	{
		SDL_Surface* textureImage;

		if((textureImage = SDL_LoadBMP(toStringz(fileName))) !is null)
		{
			scope(exit)
				SDL_FreeSurface(textureImage);

			GLTexture2D texture = new GLTexture2D();
			texture.bind();

			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, minFilter);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, magFilter);

			if(mipMapping)
			{
				gluBuild2DMipmaps(GL_TEXTURE_2D, 3, textureImage.w, textureImage.h, GL_BGR, GL_UNSIGNED_BYTE,
					textureImage.pixels);
			}
			else
			{
				glTexImage2D(GL_TEXTURE_2D, 0, 3, textureImage.w, textureImage.h, 0, GL_BGR, GL_UNSIGNED_BYTE,
					textureImage.pixels);
			}
			return texture;
		}
		return null;
	}
}
